#include <iostream>
#include <set>
using namespace std;

int  c, cat, mx;
long long a, b, cb, tot;
set <int> ok;
set <int> u;

void blacktracking()
{
    if (c == cat)
    {
        if (cb < b)
            ++tot;
        return;
    }
    for (auto i:ok)
    {
        u.insert(i);
        ++c;
        cb*=10;
        cb+=i;
        blacktracking();
        cb/=10;
        --c;
        u.erase(i);
    }
}

int main()
{
    cin >> a >> b;
    if (a >= 10)
        cout << 0;
    else
    {
        cb = b;
        while (cb)
            cb/=10, ++mx;
        for (int i = a; i <= 9; ++i)
            ok.insert(i);
        for (cat = 1; cat <= mx; ++cat)
            blacktracking();
    }
    cout << tot;
    return 0;
}